Method for Broadcasting a Magnetic Stripe Data Packet from an Electronic Smart Card

ABSTRACT

Method for broadcasting a magnetic stripe data packet from an electronic card by measuring a swipe speed of the electronic card past a magnetic reader head during a swipe of the electronic card past the magnetic reader head and then adjusting a broadcast signal containing the magnetic stripe data packet according to the measured swipe speed so that the magnetic stripe data packet in the broadcast signal is read by the magnetic reader head during said swipe. The swipe speed is measured by a speed sensor. The electronic card can contain a false swipe detection means so that the capacitive sensor changes from a sleep mode to an active mode after a wake up sensor is activated during the swipe and the swipe speed is measured by the capacitive sensor while it is in the active mode before the broadcast signal is broadcast during the swipe.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to U.S. patent application Ser. No.12/726,868, filed Mar. 18, 2010, the disclosure of which is specificallyincorporated herein by reference. The present application is acontinuation application of Ser. No. 12/822,031, filed Jun. 23, 2010,the disclosure of which is specifically incorporated by reference. Thepresent application is also a continuation-in-part of U.S. patentapplication Ser. No. 13/102,991, filed May 6, 2011, which is acontinuation of U.S. Ser. No. 12/726,868, now issued as U.S. Pat. No.7,954,724, which was a continuation application of U.S. Ser. No.11/413,595, filed Apr. 27, 2006, which was a continuation-in-partapplication of U.S. Ser. No. 11/391,719, filed Mar. 27, 2006 and whichalso claimed the priority benefit of U.S. Ser. No. 60/675,388, filedApr. 27, 2005, all of which are specifically incorporated herein byreference.

FIELD OF THE INVENTION

The present invention is in the field of electronic smart cards, andmore particularly to an electronic smart card that can broadcast amagnetic stripe data packet so that it can be read by a magnetic cardreader during a swipe of the electronic card.

BACKGROUND OF THE INVENTION

The United States primarily relies upon credit and debit cards having noelectronics that are readable by a magnetic stripe card reader. Outsidethe United States, many countries rely upon smart cards that do notcontain a magnetic stripe but are readable by smart card readers. Eachoption has its advantages and disadvantages, and there are many reasonswhy both cards currently exist.

It has long been desired to create a single card usable both inside theUnited States with magnetic stripe readers and outside the United Stateswith smart card readers that offers the advantages of both cards whileminimizing the disadvantages of both cards. Such a card not only has thepromise of saving billions of dollars a year in fraud, but it also hasthe promise of opening many other uses for the card, and generatingenormous savings related to combining multiple cards into a single card.Yet, to date, it does not exist.

The prior art includes many patents that propose just such a card, butnone has yet been commercialized. Given the long felt need for such acard, and the enormity of the problems it could solve, and the attemptsby a great many to solve the problems associated with creating such acard, one has to ask why such a card is not yet available. The reasonsare many. Cost and manufacturability are two primary reasons why such acard has not yet been commercialized, but there are other reasons aswell. Such reasons include, but are not limited to, reasons relating tosecurity, privacy, standards, and several other issues that must beaddressed before such a card can be widely deployed.

The present invention recognizes and solves a problem that has preventedelectronic smart cards from broadcasting a magnetic stripe data packetreadable by a magnetic card reader during a swipe of the electronic cardpast a magnetic reader head.

SUMMARY OF THE INVENTION

The present invention is generally directed to a method for broadcastinga transaction specific magnetic stripe data packet from an electroniccard by measuring a swipe speed of the electronic card past a magneticreader head during a swipe of the electronic card past the magneticreader head and then adjusting a broadcast signal containing thetransaction specific magnetic stripe data packet according to themeasured swipe speed so that the transaction specific magnetic stripedata packet in the broadcast signal is read by the magnetic reader headduring said swipe.

The swipe speed is measured by a speed sensor. The electronic card cancontain a false swipe detection means so that the speed sensor changesfrom a sleep mode to an active mode after a wake up sensor is activatedduring the swipe and the swipe speed is measured by the speed sensorwhile it is in the active mode before the broadcast signal is broadcastduring the swipe.

The broadcast signal is adjusted by varying a current used to broadcastsaid broadcast signal, the transaction specific magnetic stripe datapacket can have a track 2 data packet and/or a track 1 data packet andcross talk in the magnetic reader head is prevented by use of a crosstalk blocker so as to prevent cross talk.

The electronic card is first activated from an off state to a sleepmode, then converted to an active mode after a wake up sensor isactivated during a swipe of the electronic card past a magnetic readerhead, and then the swipe speed of the electronic card past the magneticreader head during the swipe is measured and used to adjust a broadcastsignal containing a transaction specific magnetic stripe data packetwhich is broadcast during the swipe so that the magnetic reader headreads the magnetic stripe data packet. False swipe detection can beprevented by measuring movement past an outer detection point and aninner detection point of a capacitive sensor used to measure swipespeed. The broadcaster does not need to be activated until theelectronic card is in the active mode.

Accordingly, it is a primary object of the present invention to providea method for broadcasting a transaction specific magnetic stripe datapacket from an electronic card so that it is read by a magnetic cardreader during a swipe of the electronic card.

This and further objects and advantages will be apparent to thoseskilled in the art in connection with the drawings and the detaileddescription of the invention set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the back side of an electronic smart card in accordancewith the present invention with a back cover removed and certaincomponents shown diagrammatically on a printed circuit board (“PCB”).

FIG. 2 depicts the back side of an electronic smart card in accordancewith the present invention with a back cover in place.

FIG. 3 depicts a front side of an electronic smart card in accordancewith the present invention with a front cover in place.

FIG. 4 depicts an alternative arrangement of a back side of anelectronic smart card in accordance with the present invention with aback cover in place.

FIG. 5 depicts a trip switch used in a preferred embodiment of thepresent invention looking down onto a PCB on which the trip switch isconstructed. FIG. 6 is a cross sectional view of the trip switch takenalong view 6-6 of FIG. 5. FIG. 7 illustrates the electronic functioningof the trip switch of FIG. 5.

FIG. 8 depicts a speed sensor used in a preferred embodiment of thepresent invention looking down onto a PCB on which the speed sensor isconstructed.

FIG. 9 is a cross sectional view of the speed sensor of FIG. 8 with arepresentation of a reader head pressing against the speed sensor duringa swipe.

FIG. 10 illustrates the electronic functioning of the speed sensor ofFIG. 8.

FIG. 11 illustrates the charge transfer working principal used incapacitive sensors.

FIG. 12 illustrates a processor or micro controller measuring the numberof charge transfer cycles and determining the speed of a card swipeusing the touch-profile method.

FIG. 13 illustrates a capacitive/swipe sensor's touch profile(right/left side pad) generation when a reader head travels over acapacitive sensor pad situated at left/right side of an electronic smartcard according to a preferred embodiment of the present invention. Note,however, in an actual case, the capacitive sensor pad on the cardtravels over the reader head.

FIG. 14 is a flow chart illustrating the steps of a preferred embodimentin which a broadcaster is activated by use of sensors.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be discussed in connection with one ormore preferred embodiments shown in the Figures. In the Figures and thefollowing more detailed description, numerals indicate various featuresof the invention, with like numerals referring to like featuresthroughout both the drawings and the description. Although the Figuresare described in greater detail below, the following is a glossary ofthe elements identified in the Figures.

1 electronic smart card

2 printed circuit board (PCB)

3 extra piece of PCB added to PCB 2

5 front cover of card 1

6 back cover of card 1

15 front side of card 1

16 back side of card 1

20 trip switch

21 distance between extra PCB pieces needed to complete electrical tripswitch 20

22 extra piece of PCB added to PCB 2

23 electrical trace

24 extra piece of PCB added to PCB 2

25 extra piece of PCB added to PCB 2

26 electrical trace

27 extra piece of PCB added to PCB 2

30 capacitor speed sensor

31 outer detection pad

32 inner detection pad

33 piece of PCB added to PCB 2

34 conductive pad

40 broadcaster

43 strip of magnetic tape

50 electronics

51 processor or micro controller unit (MCU)

60 battery

61 capacitive sensor

62 capacitive sensor

63 capacitive sensor

64 on/off button

65 7816 chip plate

66 security hologram

67 signature strip

71 account number

72 account number

73 account number

74 expiration date and CVV for account number 71

75 expiration date and CVV for account number 72

76 expiration date and CVV for account number 73

77 light emitting diode (LED)

81 branding

82 embossed primary account number

83 embossed user name

84 embossed expiration date

100 reader head

A preferred embodiment of the present invention provides an electronicsmart card, shown generally as 1 in FIG. 3, having a printed circuitboard (PCB) 2 enclosed within a front cover 5 on a front side 15 and aback cover 6 on a back side 16. Back side 16 of card 1 is orientatedsuch that it functions similarly to a back side of a conventional creditcard having a magnetic stripe on its back side.

Electronic smart card 1 should be usable in situations where a smartcard reader is used and in applications where a card is read by aconventional magnetic stripe reader. Accordingly, electronic smart card1 should satisfy the ISO 7816 standard for smart cards, incorporatedherein by reference, and the ISO 7810 standard for transaction cards,also incorporated herein by reference. Details relating to both ISOstandards and electronics, dimensions and other details needed to meetboth standards, is set forth in U.S. Patent Application Publication20070034700, published Feb. 15, 2007, entitled “Electronic cards andmethods for making same,” the disclosure of which is specificallyincorporated herein by reference and hereinafter referenced as“Electronic Cards.”

Electronic smart card 1 should have two processors or micro controllersfor performing secure and non-secure functions as detailed in ElectronicCards. Alternatively, a single processor or micro controller can be usedto replace the secure and non-secure processors described in ElectronicCards so long as it has suitable input/output ports and divided memoryso that it functions equivalently to the secure and non-secureprocessors described in Electronic Cards. For purposes of the presentinvention, it will be presumed that MCU 51 is such a combined processoror a combination of a secure and non-secure processor as described inElectronic Cards.

Processor or micro controller unit 51 (whether it be a single processoror a combination of two processors) is mounted to PCB 2 as are otherelectronics, generally designated as 50, necessary for electronic smartcard 1 to function.

Details of electronics 50 are not critical to the present invention andshould be well within the skill of a person of ordinary skill in theart, especially when viewing the teachings of Electronic Cards and theteachings of the present invention.

Front side 15 of electronic smart card 1 (see FIG. 3) has a 7816 chipplate 65 and can having branding 81, an embossed primary account number82, an embossed user name 83 and embossed expiration date 84. Embossedprimary account number 82, embossed name 83 and embossed expiration date84 are located according to the ISO 7816 standard and meet itsrequirements.

Back side 16 of electronic smart card 1 (see FIG. 4) has a signaturestrip 67 and hologram 66 that satisfy the ISO 7816 standard (likeconventional transactions cards). However, unlike conventionaltransaction cards, electronic smart card 1 has three capacitive sensors(61-63) for accessing three different accounts whose account numbers(71-73) and combined expirations dates with CVV (74-76, respectively)are printed on back cover 6. LEDs 77 alongside sensors 61-63 indicate toa user which, if any, of account numbers 71-73 has been selected foruse. (Note that in an especially preferred embodiment account number 71is the same as embossed primary account number 82 and embossedexpiration date 83 is contained in expiration date with CVV 74.) Alsoaccessed from back side 16 is an on/off switch 64. A strip of magnetictape 43 is also located on back cover 6 and positioned so as to preventcross talk between a reader head that can detect both track 1 and track2 data from a conventional magnetic stripe. Such positioning is keyed tolocation of where track 1 and track 2 data would be in conventionalmagnetic stripe card following ISO standard 7810 and is thus locatedbetween where such data would be in a such a card.

Electronic smart card 1 of the present invention uses a broadcaster 40for broadcasting a broadcast signal during a swipe of the card so that amagnetic stripe reader head can read a transaction specific magneticstripe data packet contained in the broadcast signal. The broadcastsignal may contain track 1 and/or track 2 data (or, if desired, track 3data as well). The present invention is not concerned with details of abroadcaster, although such a broadcaster can actually take the form ofseparate broadcasters so that a given broadcaster only broadcasts thedata for a given track of data as is explained in greater detail inElectronic Cards. It should be noted, however, that it has been foundthat the problem of cross talk (discussed in greater detail inElectronic Cards) can be effectively dealt with by use of a magneticstripe positioned on back cover 6 as already noted above. This method ofdealing with cross talk is much simpler, cheaper to implement and moreefficient than broadcasting a cancellation signal to prevent cross talkand represents a significant advance in the prevention of cross talk inan electronic card that broadcasts data to a magnetic stripe readerhead.

Attached to PCB 2 oriented toward back side 16 of card 1 are two tripswitches 20 and two speed sensors 30 oriented toward the side ends ofcard 1 in the proximate area of card 1 where a magnetic stripe islocated in a conventional magnetic stripe card according to ISO standard7810. Two trips switches and speed sensors are included so thatelectronic card will function when read by a magnetic stripe reader ineither a left to right or right to left swipe direction.

Each trip switch 20 is located such that it will be triggered by amagnetic reader head 100 during a swipe of electronic smart card 1before magnetic reader head passes over any portion of broadcaster 40. Atrip switch is depicted in FIGS. 5-7. Trip switch 20 functions as asimple on/off switch that is triggered when magnetic reader head 100passes over it. In an especially preferred embodiment, trip switch 20has two PCB pieces 23 and 25 connected by trace 24 built upon PCB 2 anda second set of two PCB pieces 26 and 28 connected by trace 27 alsobuilt upon PCB 2. Two sets of PCB pieces are used to ensure that readerhead 100 passes over one of the sets (of course, a larger set of PCBpieces could be used, but it would be less efficient and moreexpensive). The distance 21 between the two sets of PCB pieces 23/25 and26/28 is less than the width of magnetic reader head 100 so that tripswitch 20 will be triggered as magnetic head 100 passes over it. FIG. 7shows a conceptual diagram of the function of trip switch 20. Each tripswitch 20 is electrically connected to MCU 51. MCU 51 is triggered to anactive mode when it receives an activation signal from one of tripswitches 20.

Although electronic smart card 1 can function without use of tripswitches 20, they are included in an especially preferred embodimentbecause they help to prolong the life of battery 60. Because electronicsmart card 1 uses a broadcaster 40, broadcaster 40 will consume energyfrom battery 60 when it is in an active mode. When a user activateselectronic smart card 1 by turning it on through on/off button 64,electronic card 1 will be consuming energy from battery 60. However,through use of trip switches 20, broadcaster 40 will remain in a sleepmode and not be powered up into an active mode until one of tripswitches 20 is activated, thus minimizing power consumption bybroadcaster 20.

Speed detection is critical for MCU 51 of electronic smart card 1 todetermine the rate of broadcast by broadcaster 40. There are variousways of determining the speed of card 1 travelling across a reader head,such as photo sensor. However, it is especially preferred that acapacitive sensor is used for speed detection because it offers theadvantages of a very low profile, relatively low cost and relatively lowpower consumption.

Each speed sensor 30 is located such that it will be triggered bymagnetic reader head 100 after it has activated a trip switch 20 andbefore magnetic reader head 100 passes over that portion of broadcaster40 that conveys a broadcast signal to magnetic reader head 100 during aswipe of electronic smart card 1. Although speed sensors 30 can takedifferent forms, in an especially preferred embodiment, each speedsensor 30 is comprised of a capacitive sensor having an inner detectionpad 31 and an outer detection pad 32, the outer detection pad beingcloser to the outside side edge of card 1. Outer and inner detectionpads 31 and 32 are comprised of PCB pieces 33 and a conductive layer ofmaterial 34 (such as copper or silver). The purpose of PCB pieces 33 isto move conductive layer of material 34 up closer to reader head 100.Outer and inner detection pads 31 and 32 are electrically connected toMCU 51.

Capacitive speed sensors 30 work based on the principle ofcharge-transfer signal acquisition for robust sensing. The acquisitionmethod charges a conductive layer of material (or pad) 34 of unknowncapacitance (Cx) to a known potential. The resulting charge istransferred into a measurement capacitor (Cs). The charge cycle isrepeated until the voltage across Cs reaches the required voltage. Thenumber of charge-transfer cycles it takes to reach a voltage (Vih) iscalled signal level of measurement capacitor Cs. Placing a finger on thetouch surface introduces an external capacitance (Ct) that increases theamount of charge transferred each cycle and hence it reduces the signallever/number of transfer cycles required for Cs to reach the voltage.When the number of cycles reduces more than the present threshold, thenthe sensor is reported as in detect whereas the sensor identifies afalse detect when the number of cycles exceeds the present threshold.

Based on the charge transfer principle, the dielectric of the capacitoris the material between the magnetic reader head and pad 34. In anembedded design, dielectric of the capacitor is formed by overlay andFR4 material whereas in a chip plate design, dielectric of the capacitoris formed by the overlay alone. In both designs, the conductive padforms one of the electrodes of a capacitor. The magnetic reader headacts as the other electrode of the capacitor, which also provides avirtual ground to the resulted capacitor. This is shown in FIG. 12.There are two different especially preferred designs for a capacitivesensor useful in the present invention as a swipe speed detectionsensor. The first design is using a copper pad embedded on a top siderear of main PCB 2 and the second design is using a 0.4 mm thick chipplate PCB to elevate the copper pad off of top side rear of main PCB 2as shown in FIG. 8.

Keeping the sense capacitance value (C_(s)) unchanged, the separationbetween the magnetic reader head and the capacitive sensor is criticalfor the sensitivity of the capacitive sensor. The larger the separation,the less sensitive the capacitive sensor it is. Comparing the twodesigns, the separation between the magnetic reader head and thecapacitive sensor is 0.075 mm in the chip plate design of FIG. 8. Thisis a much smaller gap distance as compared to approximately 0.5 mmseparation distance in the embedded pad design. Therefore, it isexpected that the capacitive sensor in the chip plate design has bettersensitivity as compared to that in the embedded pad design.Nevertheless, the embedded pad design is simpler as compared to the chipplate design.

The firmware implementation for swipe speed, inch per second (S_(ips)),detection will be based on the time stamps, T₁ and T₂, marked at theedges of the sensor's touch profile, which is generated when the readerhead travels over the capacitive sensor pad of length L_(pad). It isimportant that the detection method is independent of the magneticreader head. This is because the capacitance and the dimension of themagnetic reader head are different from one reader head to another. Thetouch-profile method depends only on the length of the sensor pad andany variation of the magnetic reader head will not affect the speeddetection accuracy. Hence, the swipe speed in inches per second(S_(ips)) is calculated as:

S _(ips) =L _(pad)/(T ₂ −T ₁)  Equation 1

The sequential flow of firmware in SWIPE state (see FIG. 14) is detailedas:

-   -   A non-secure chip shall be put into deep sleep mode until it is        woken up by the wake up source, WDT timeout/External interrupt,        to transition into active/normal state.    -   If the chip is woken up by WDT timeout then it checks for Swipe        Long Timeout elapse and enters back to sleep mode until the        swipe timeout elapse.    -   If the chip is woken up by an external interrupt source, from        one of the trip switch/sensors populated at either side of the        card, which in turn decides the direction of the swipe, enables        the swipe/capacitive sensor touch profile capture for speed        detection until Swipe Short Timeout elapse.    -   As shown in the above, FIG. 13, the difference count from        reference to touch is dynamically monitored until the difference        count reaches the maximum, where the time stamp T₁ is marked.        The time stamp T₂ shall be marked when the difference count        starts decreasing from its maximum value.    -   The swipe speed in inch per second (S_(ips)) will be calculated        based on the profile time stamps and capacitive sensor pad        length by using Equation A.    -   The swipe speed calculated shall be compared with minimum,        medium and maximum speed threshold levels to decide the        broadcast data rate through coil terminals. It is especially        preferred that there be three discrete levels to broadcast data        by broadcaster 40 based on the detected speed:        -   a) Slow 5 IPS≦Swipe Speed<10 IPS , data rate=3750 bits/sec        -   b) Medium 10 IPS≦Swipe Speed<20 IPS, data rate=7500 bits/sec        -   c) Fast Swipe Speed≧20 IPS, data rate=10000 bits/sec

Although the data transmission rate changes according to different swipespeed range, the read amplitude remains constant. If swiping aconventional mag-stripe card at the speed of 50 IPS produces readamplitude of 3Vp-p, then electronic smart card 1 will produce the sameread amplitude regardless of swipe speed and broadcast card with the MCUwill produce read amplitude of 6Vp-p.

If the set data rate is within the boundary condition, the swipe statewill be transitioned to BROADCAST state by ‘gSwipe2Broadcast( )’function.

After BROADCAST state, the chip enters back to SWIPE state until theSwipe Short Timeout elapse.

While the invention has been described herein with reference to certainpreferred embodiments, those embodiments have been presented by way ofexample only, and not to limit the scope of the invention. Additionalembodiments thereof will be obvious to those skilled in the art havingthe benefit of this detailed description. For example, the presentdisclosure and FIGS. 2 and 4 illustrate an electronic smart card havingthree different visible account numbers, whereas additional accountnumbers could be added. Also, a visual display device could be added fordisplaying the account chosen by a user. Further modifications are alsopossible in alternative embodiments without departing from the inventiveconcept.

Accordingly, it will be apparent to those skilled in the art that stillfurther changes and modifications in the actual concepts describedherein can readily be made without departing from the spirit and scopeof the disclosed inventions as defined by the following claims.

1. A method comprising broadcasting a transaction specific magneticstripe data packet from an electronic card by measuring a swipe speed ofthe electronic card past a magnetic reader head during a swipe of theelectronic card past the magnetic reader head and then adjusting abroadcast signal containing the magnetic stripe data packet according tothe measured swipe speed so that the magnetic stripe data packet in thebroadcast signal is read by the magnetic reader head during said swipe.2. The method of claim 1 wherein the swipe speed is measured by a speedsensor.
 3. The method of claim 2 wherein the electronic card contains afalse swipe detection means.
 4. The method of claim 3 wherein the speedsensor changes from a sleep mode to an active mode after a wake upsensor is activated during the swipe and the swipe speed is measured byspeed sensor while it is in the active mode before the broadcast signalis broadcast during the swipe.
 5. The method of claim 4 wherein the wakeup sensor is a trip switch.
 6. The method of claim 5 wherein thebroadcast signal is adjusted by varying bit rate used to broadcast saidbroadcast signal.
 7. The method of claim 1 wherein the magnetic stripedata packet is comprised of a track 2 data packet.
 8. The method ofclaim 7 wherein the magnetic stripe data packet is further comprised ofa track 1 data packet.
 9. The method of claim 8 wherein cross talk inthe magnetic reader head responsible for reading track 1 data isprevented by use of a cross talk blocker.
 10. The method of claim 9wherein the cross talk blocker is a cancelation coil located on theelectronic card so as to prevent cross talk.
 11. A method, comprising:activating an electronic card from an off state to a sleep mode;changing the electronic card from the sleep mode to an active mode aftera wake up sensor is activated during a swipe of the electronic card pasta magnetic reader head; measuring a swipe speed of the electronic cardpast the magnetic reader head during the swipe; using the swipe speed toadjust a broadcast signal containing a transaction specific magneticstripe data packet; and broadcasting the broadcast signal during theswipe so that the magnetic reader head reads the magnetic stripe datapacket.
 12. The method of claim 11 wherein a false swipe detection isprevented by measuring movement past a speed sensor.
 13. The method ofclaim 11 wherein a broadcaster in the electronic card is activatedduring the active mode.
 14. The method of claim 13 wherein the broadcastsignal is adjusted by varying a bit rate used by the broadcaster tobroadcast said broadcast signal.
 15. The method of claim 13 wherein thebroadcaster is comprised of a track 2 broadcaster that broadcasts atrack 2 data packet and a track 1 broadcaster that broadcasts a track 1data packet.
 16. The method of claim 11 wherein a cross talk blocker isused to prevent the magnetic reader head from reading a particular trackdata packet in a reading area of the magnetic reader head that is notmeant to read the particular track data packet.